Can a T420s set up with the fingerprint reader replace my password login? More specifically, is there a way to make Windows allows me to log in with a fingerprint and not my Windows password?
Note: This question can apply to any system with a fingerprint reader
Technically, you can have Windows password+fingerprints for accessing Windows, but not have fingerprint alone.
This is not possible if you meant to remove Windows password entirely and access the Windows purely with fingerprint reader.
By removing your Windows password, your system is wide open for attack. Windows security is based on your password. Technically, all the fingerprint software does is translate your fingerprint into the password, and then feed the password into Windows on your behalf. Thus you still need to have a strong Windows password. There is no way to remove passwords and then only have fingerprint security - that's simply not the design of Windows.